Blasting cap fuse protector



NOV. 6, 1945. J cuR l'ss 2,388,310

BLASTING GAP FUSE PROTECTOR Filed Sept. 1, 1943 FIG. I. F|G.2..

Patented Nov. 6, 1945 arren stares insane PAT E r caries 8 Claims.

The invention relates to protectors for the joint between the blasting caps and fuses having ends inserted in the caps at the time the charges are It has been customary to mount a number of doughnut-like rolls of thin rubber material upon a magazine-forming stick and to roll them off the stick onto the end of a cap, then to insert the fuses and then to unroll a portion of the tube back onto the fuse, all as described in W. E. Miller Patent 636,919, issued November 14, 1899 and Patent 931,454, issued August 1'7, 1909. In a copending application I have disclosed a unit consisting of a blasting cap with a fuse of this general type preassembled with the cap, thus avoiding the insertion of a carrier stick into the end of the fuse and the delay in manipulating the protector off the stick onto th cap and then back onto the fuse.

The main object of the present invention is to further simplify the use of protectors of this general type, and this is accomplished by providing a protector unit readily applied individually to the cap and fuse, other general objects of the present invention being to provide a secure assembly of the fuse and cap and the Waterproofing of the joint between them.

These objects are attained by the structure illustrated in the accompanying drawing in which- Figure 1 is a side elevation of the protector device sectioned in part and ready for application to a blasting cap or to a fuse.

Figure 2 is an end elevation of the device.

Figure 3 is a longitudinal section taken through a blasting cap showing a fuse inserted in its open end and having a protector device applied to the cap and fuse in operating position.

Figure 4 corresponds to Figure 3 but illustrates another form of the invention.

Figure 5 illustrates another arrangement of the protector and its assembly with a cap and fuse.

The device comprises a relatively short sleeve I and a relatively long tube 2, the latter being rolled inwardly from each end over and over to form doughnut-like roll portions 3 and 4 around the end portions of the sleeve. Preferably the sleeve and tube are made of rubber-like material, the sleeve being relatively thick so as to resist undue deformation when handled and applied as described below and the tube being relatively thin and normally of smaller diameter than the sleeve but stretchable so as to surround the sleeve as described.

When the device is to be used, it may be grasped in one hand and a cap C gr sp in the other hand and the open end of the cap inserted into sleeve 2, the latter having an internal diameter slightly less than the outside diameter of the cap but yielding to axial thrust of the cap to receive the end of the cap. After the cap has been inserted about half way through the sleeve, an end of the fuse F may be inserted through the v other end of the sleeve and into the open end of the cap, as shown in Figure 3. Then the rolls 3 and 4 are unrolled over the fuse and cap respectively, as indicated at 5 and 6 (Figure 3), thus securing the cap and fuse together, with the end of the fuse in contact with the explosive in the cap, and forming an elongated joint between the fuse and cap which is resistant to the passage of dirt and moisture. Preferably each end of the tube has an integral bead or rib 8 which facili tates its rolling and unrolling manually but tends to hold it against accidental unrolling.

With this arrangement, each protector is an individual unit readily applicable to the cap and fuse and it will be unnecessary to preassemble the protector and the cap or to utilize a loading stick or other equipment for applying the protector to the fuse and cap. The device as illustrated is constructed the same at both ends and is readily applied by feel, avoiding the necessity or desirability of light.

The sleeve and cap may comprise a single integral member having a thickened portion for application over the cap and a thinner portion to be rolled onto the thicker end and to be unrolled therefrom onto the fuse.

Figure 4 illustrates another form of the invention in which the sleeve III of the sealing device has the same internal diameter as the external diameter of the fuse F-I and abuts against the end of the cap C!. The rubberlike tube II is rolled upon sleeve 10 initially as is the tube shown in Figure 1 and is unrolled upon the fuse and cap after the end of the fuse has been inserted into the end of the cap. Prior to this insertion it will be necessary to slip the protector sleeve over the fuse and then, after the fuse has been inserted in the cap, bring the protector sleeve back to the cap and unroll the tube as shown. Sleeve Ill may be of plastic, rubber, metal, or other material and may well be formed of metal tubing corresponding to that from which the cap itself is formed.

Figure 5 illustrates another arrangement in which the sleeve 20 is slid over the fuse F-Z a substantial distance from the end of the latter and the rubber tube 2| is arranged to be unrolled from one end only of the sleeve and to the construction may be varied otherwise than as described Without departing from the spirit of the invention, and the exclusive use of such modifications of the invention as come scope of the claims is contemplated.

What is claimed is: 1. A protector for the joint between a blasting cap member and a fuse member associated therewith, comprising a sleeve open from end to end and. adapted to receive the end portions of said,

members in its opposite, ends, and a length of flexible, elastic, waterproof material surrounding said sleeve and rolled inwardly from each of its outer ends onto thesleeve endwise on itself and adapted to be unrolled in opposite directions from thesleeve onto the adjacent portions of the members inserted in the ends of the sleeve within the inserted member and to seal the joint between the member and sleeve.

4. A device for uniting a blasting cap member and a fuse member leading thereto, comprising a substantially rigid sleeve open at both ends and adapted to slidably receive in one end the end portion of one of said members, and a tube of thin elastic, flexible, waterproof material rolled from its end on itself onto the sleeve and being stretched in such rolling and adapted to be unrolled from the sleeve onto the other member and to contract thereon to secure the members together in fixed relation and to form a watertight joint between them.

5. A device as described in claim 4 in which the outer end of the tube terminates in a thickened rib whereby the rolling of the tube onto the and to contract about the members'to form a waterproof joint between the members and the sleeve.

2; A protector of the class described. comprising a relatively short cylindrical sleeve having an inside diameter slightly less than the outside diameter of a blasting cap to which it is to be applied and formed of material of sufiicient elasticity to yield to receive in one end the end portion of a blasting cap and of sufficient thickness to resist doubling when held manually and having the open end of ablasting cap thrust into it, and a tube of flexible material rolled over and over endwise onto the sleeve and ,adapted'to be unrolled from the sleeve over a fuse inserted in the cap and being of sufiicient elasticity to firmly grip the fuse and to seal the joint between the cap and fuse.

'3. A protector of the class described comprising a relatively short cylindrical sleeve having an inside diameter slightly less than the outside diameter of a blasting cap member and a fuse member inserted therein, to which the protector is to be applied, and being of material of sufficient elasticity to yield to receive in. its opposite ends the end portions of said members and being of sufiicient rigidity to resist doubling when held manually and having the ends of said members thrust into it, and a tube of flexible material rolled over and over endwise onto each endof the sleeve, with its inner portions secured tothe sleeve, and adapted to be unrolled from the sleeve over the member inserted in that end of the sleeve and being of sufficient elasticity to firmly grip the sleeve is facilitated and maintained.

6. A device for uniting a blasting cap memher and a fuse member leading thereto and comprising a vflexible rubber sleeve adapted to be slidendwise. over said members, each end of the sleeve having a tube of relatively thin rubber material rolled from its end inwardly over itself onto the sleeve and being stretched in such roll-, ing, and adapted to be unrolled from the sleeve onto a member inserted therein to secure the member and sleeve together and to form a Watertight joint between them. a Y

7.. A device for uniting a blasting cap member and a fuse member leading thereto, comprising a. substantially rigid sleeve open at both ends and adapted to slidingly fit over the fuse member with which it is to be used and having an internal diameter corresponding ,to' the outside di ameter of the fuse so. that the end of the sleeve mayl abut the end of a. cap in which the fuse is inserted, there being a tube of thin rubber material rolled from itself and on its end onto the sleeve and being stretched in such rolling and adapted to beunrolled from the sleeve onto the cap member and to contract thereon to secure the. members together and to form a water-tight joint between them.

8. As a complete article of manufacture, applicable to a blasting cap member and a fuse member formed separately, a device readily applicable to said members to hold them assembled and to form a water-tight joint'between them andrcomprising a sleeve open at both ends and adaptedvto receive in each end the end portion of ,a respective one of said members, and a tube of flexible, elastic,- waterproof material withone. end connected to the sleeve and with its remaining portion rolled endwise on itself. and over the sleeve to form a roll about the connected end and sleeve and adapted tobe unrolled from the sleeve onto the member inserted in the sleeve and to tightly grip the member. I

JOHN s. CURTISS; 

